{
  "abstract": "Background: Normobaric hypoxic resistance training (NHRT) studies describe the hypoxic prescription using the fraction of inspired oxygen (FiO₂) or simulated altitude. However, FiO₂ is an external setting and may not fully represent the hypoxic stimulus experienced during training. Training SpO₂ responses, the hypoxia-delivery method, facility volume, gas flow, ventilation, CO₂, humidity and temperature may affect the exposure environment. These variables are important for interpreting and comparing NHRT studies, but their reporting has not been systematically evaluated.\n\nMethods: This evidence map assessed reporting of hypoxic exposure and air quality in chronic NHRT studies and conducted exploratory meta-analyses when outcomes and data were comparable. The primary evidence map comprised 16 independent chronic NHRT cohorts. Reporting completeness was assessed in this set and repeated in an extended 17-study set that included one additional air-quality reference study. Thirteen independent primary cohorts contributed to at least one exploratory meta-analysis. NHRT-versus-NRT syntheses used random-effects models and Hedges-corrected standardised mean differences.\n\nResults: FiO₂ or simulated altitude was reported relatively well, whereas training SpO₂, CO₂, humidity, temperature, ventilation, space and flow-related variables were underreported. Thirteen independent cohorts contributed to at least one exploratory meta-analysis. Lower-limb maximal strength (7 studies; SMD = 0.07, 95% CI -0.26 to 0.41; I2 = 0%) and lean mass (5 studies; SMD = 0.12, 95% CI -0.25 to 0.49; I2 = 0%) did not show a clear additional advantage of NHRT over NRT. Whole-body body fat percentage showed an unstable numerical direction favouring NHRT (5 studies; SMD = -0.33, 95% CI -0.78 to 0.12; I2 = 23.2%). Local muscle morphology and local muscular endurance outcomes were supported by few studies and should be interpreted as exploratory.\n\nConclusions: Existing NHRT studies report FiO₂ or simulated altitude relatively well, but actual exposure conditions and internal hypoxic responses remain incompletely described. Exploratory meta-analyses did not show that NHRT was superior to NRT for common outcomes related to strength, body composition or local muscle morphology. Future NHRT studies should report not only FiO₂, but also hypoxia-delivery method, internal oxygenation responses and air-quality control conditions.\n\nSystematic review registration: PROSPERO CRD420261405733.\n\nSupplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s13102-026-01943-y.",
  "abstract_shown": true,
  "affiliations": [
    "College of Physical Education and Health, Guangxi Normal University, Guilin, Guangxi China"
  ],
  "article_type": "review article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Zhiyu Guan"
    },
    {
      "affs": [
        0
      ],
      "name": "Ziwen Wang"
    },
    {
      "affs": [
        0
      ],
      "name": "Chuangui Mao"
    },
    {
      "affs": [
        0
      ],
      "name": "Weiguo Liu"
    },
    {
      "affs": [
        0
      ],
      "name": "Cheng Zhang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1cnp8r8wd8q3w.bib",
  "cited_by": 0,
  "doi": "10.1186/s13102-026-01943-y",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13729312/",
  "id": "1cnp8r8wd8q3w",
  "issns": [
    "2052-1847"
  ],
  "landing_url": "https://doi.org/10.1186/s13102-026-01943-y",
  "language": "en",
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Systematic Review"
    ],
    [
      "openalex",
      "2737|High Altitude and Hypoxia"
    ]
  ],
  "openalex": "W7172536243",
  "pdf_url": null,
  "pmcid": "PMC13729312",
  "pmid": "42977993",
  "published": "2026-08-06",
  "publisher": "BMC",
  "ris": "https://research.draconitic.com/paper/1cnp8r8wd8q3w.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T12:22:05Z",
      "native_id": "PMC13729312",
      "source": "pmc",
      "url": "https://doi.org/10.1186/s13102-026-01943-y"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2737|High Altitude and Hypoxia",
      "subfield": "physiology"
    }
  ],
  "title": "Hypoxic exposure and air-quality reporting in normobaric hypoxic resistance training: a systematic evidence map and exploratory meta-analysis",
  "title_text": "Hypoxic exposure and air-quality reporting in normobaric hypoxic resistance training: a systematic evidence map and exploratory meta-analysis",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T12:22:05Z",
  "url": "https://research.draconitic.com/paper/1cnp8r8wd8q3w",
  "venue": "BMC Sports Science, Medicine and Rehabilitation",
  "versions": []
}